The present invention relates to a printing apparatus, printing method, and computer-readable memory for printing with a plurality of types of printing agents on a printing medium by using a printing element.
The present invention also relates to a printing apparatus, printing method, and computer-readable memory for printing with a plurality of types of printing agents on a printing medium by using a printhead with one or a plurality of printing elements.
Printing apparatuses such as an ink-jet printer have conventionally been studied and developed widely and are popular. A larger number of gray levels, a higher speed, and a lower price have been sought for in the printing apparatus.
Among these demands, a larger number of gray levels can be effectively met by using a low-concentration printing agent. When a low-concentration printing agent is used, to obtain a desired image density, a large number of dots must be printed with a low-concentration printing agent at substantially one position on a printing medium in an overlaying manner, or so-called multiple printing must be performed, and a problem such as an ink overflow may undesirably occur in, e.g., an ink-jet printer.
In particular, in an ink-jet printer for printing a full-color image by using cyan, magenta, yellow, and black inks, it is difficult to decrease the concentrations of all inks due to the reason described above.
When a yellow ink or a black ink is represented by a color ink of, e.g., yellow, that cannot be visually recognized easily, or a color ink such as black that can be obtained by mixing inks of any other colors (cyan, magenta and yellow), the yellow ink or the black ink is obtained by a dark ink without using any light ink.
Then, the maximum numbers of ink dots of the same color overlaid at substantially one position on the printing medium (to be referred to as maximum multiple printing counts hereinafter) inevitably differ depending on the ink colors (types).
However, in printing using a plurality of types of printing agents with different maximum multiple printing counts, if the number of printing elements for each of the plural printing agent types are the same, the following inconveniences are bound to occur.
For example, when the number suitable for one printing element with a small maximum multiple printing count equal to the number of other printing elements, in printing using a printing agent with a large maximum multiple printing count, the printing speed decreases because the number of printing elements is short.
Alternatively, when the number suitable for one printing element with a large maximum multiple printing count equal to the number of other printing elements, in printing using a printing agent with a small maximum multiple printing count, one or more printing elements are not used at all or not used for a long period of time, leading to waste, i.e., an increase in cost.
In any case, in printing using a plurality of types of printing agents with different maximum multiple printing counts, if the number of each of the printing elements for each of the plural types of printing agents are the same, the above inconveniences are bound to occur.
The present invention has been made in view of the above problems, and has as its object to provide a printing apparatus, printing method, and computer-readable memory that can prevent both xe2x80x9ca decrease of the printing speed caused because the number of printing elements is shortxe2x80x9d and xe2x80x9can increase in cost caused because one or more printing elements are not used at all or for a long period of timexe2x80x9d.
According to the present invention, the foregoing object is attained by providing, a printing apparatus for performing printing with a plurality of types of printing agents on a printing medium by using a printing element, comprising:
printing elements, for performing printing with the printing agents, in a number in accordance with a maximum multiple printing count with which dots of each one of the plurality of types of printing agents are printed in an overlaying manner at substantially one position on the printing medium.
Other features and advantages of the present invention will be apparent from the following description taken in conjunction with the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures thereof.